Composite oxide having n-type thermoelectric characteristics

ABSTRACT

The present invention provides a complex oxide having a composition represented by the formula Ln 1-x M x NiO y ; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; and 0≦x≦0.8; and 2.7≦y≦3.3, or the formula (Ln 1-x M x ) 2 NiO y ; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8; and 3.6≦y≦4.4, the complex oxide having a negative Seebeck coefficient at 100° C. or higher. The complex oxide of the invention has a negative Seebeck coefficient and low electrical resistivity and also has excellent heat resistance, chemical durability, etc., and thus can be effectively utilized as an n-type thermoelectric material in air at high temperatures.

TECHNICAL FIELD

The present invention relates to a complex oxide capable of achieving high performance as an n-type thermoelectric material, and an n-type thermoelectric material using the complex oxide.

BACKGROUND ART

In Japan, only 30% of the primary energy supply is used as effective energy, with about 70% being eventually lost to the atmosphere as heat. The heat generated by combustion in industrial plants, garbage-incineration facilities or the like is lost to the atmosphere without conversion into other energy. In this way, a vast amount of thermal energy is wastefully discarded, while acquiring only a small amount of energy by combustion of fossil fuels or other means.

To increase the proportion of energy to be utilized, the thermal energy currently lost to the atmosphere should be effectively used. For this purpose, thermoelectric conversion, which directly converts thermal energy to electrical energy, is an effective means. Thermoelectric conversion, which utilizes the Seebeck effect, is an energy conversion method for generating electricity by creating a difference in temperature between both ends of a thermoelectric material to produce a difference in electric potential. In such a method for generating electricity utilizing thermoelectric conversion, i.e., thermoelectric generation, electricity is generated simply by setting one end of a thermoelectric material at a location heated to a high temperature by waste heat, and the other end in the atmosphere (room temperature) and connecting conductive wires to both ends. This method entirely eliminates the need for moving parts such as the motors or turbines generally required for electric power generation. As a consequence, the method is economical and can be carried out without generating gases by combustion. Moreover, the method can continuously generate electricity until the thermoelectric material has deteriorated.

Therefore, thermoelectric generation is expected to play a role in the resolution of future energy problems. To realize thermoelectric generation, large amounts of a thermoelectric material that has a high thermoelectric conversion efficiency and excellent heat resistance, chemical durability, etc. will be required.

CoO₂-based layered oxides such as Ca₃Co₄O₉ have been reported as substances that achieve excellent thermoelectric performance in air at high temperatures. However, all such oxides have p-type thermoelectric properties, and are materials with a positive Seebeck coefficient, i.e., materials in which the portion located at the high-temperature side has a low electric potential.

To produce a thermoelectric module using thermoelectric conversion, usually not only a p-type thermoelectric material but also an n-type thermoelectric material are needed. However, n-type thermoelectric materials that have excellent heat resistance, chemical durability, etc., and have a high thermoelectric conversion efficiency have not yet been found. Therefore, thermoelectric generation using waste heat has not yet become practical.

In such circumstances, the development of n-type thermoelectric materials is greatly desired that are composed of low toxic and abundantly available elements, have excellent heat resistance, chemical durability, etc., and have a high thermoelectric conversion efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows X-ray diffraction patterns of the complex oxides obtained in Examples 1 and 541.

FIG. 2 schematically shows the crystal structures of complex oxides 1 and 2.

FIG. 3 is a view schematically showing a thermoelectric module comprising the complex oxide of the invention as a thermoelectric material.

FIG. 4 is a graph showing the temperature dependency of the Seebeck coefficient of the sintered complex oxides prepared in Examples 1 and 541.

FIG. 5 is a graph showing the temperature dependency of the electrical resistivity of the sintered complex oxides prepared in Examples 1 and 541.

DISCLOSURE OF THE INVENTION

The present invention has been made to solve the above problems. A principal object of the invention is to provide a novel material that achieves excellent performance as an n-type thermoelectric material.

The present inventors conducted extensive research to achieve the above object and found that a complex oxide having a specific composition comprising a lanthanide, Ni and O as essential elements and partially substituted by specific elements has a negative Seebeck coefficient and a low electrical resistivity, thus possessing excellent properties as an n-type thermoelectric material. The invention has been accomplished based on this finding.

The present invention provides the following complex oxides and n-type thermoelectric materials using the complex oxides.

1. A complex oxide having a composition represented by the formula Ln_(1-x)M_(x)NiO_(y); wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; and O≦x≦0.8; and 2.7≦y≦3.3, the complex oxide having a negative Seebeck coefficient at 100° C. or higher.

2. A complex oxide having a composition represented by the formula Ln_(1-x)M_(x)NiO_(y); wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8; and 2.7≦y≦3.3, the complex oxide having an electrical resistivity of 1 Ωcm or less at 100° C. or higher.

3. A complex oxide having a composition represented by the formula (Ln_(1-x)M_(x))₂NiO_(y); wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8; and 3.6≦y≦4.4, the complex oxide having a negative Seebeck coefficient at 100° C. or higher.

4. A complex oxide having a composition represented by the formula (Ln_(1-x)M_(x))₂NiO_(y); wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8, and 3.6≦y≦4.4, the complex oxide having an electrical resistivity of 1 Ωcm or less at 100° C. or higher.

5. An n-type thermoelectric material comprising the complex oxide of any one of Items 1 to 4.

6. A thermoelectric module comprising the n-type thermoelectric material of Item 5.

The complex oxide of the invention is a complex oxide whose composition is represented by the formula Ln_(1-x)M_(x)NiO_(y) (hereinafter referred to as “complex oxide 1”), or a complex oxide whose composition is represented by the formula (Ln_(1-x)M_(x))₂NiO_(y) (hereinafter referred to as “complex oxide 2”).

In complex oxides 1 and 2, Ln is a lanthanide and preferably is Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, or Lu. Among the above-mentioned lanthanides, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, etc., are more preferable because such elements can easily provide a single-phase sample with no impurities.

In complex oxides 1 and 2, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln. Specific examples of rare earth elements include Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu, etc. In particular, M is preferably at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, and Er because these elements can easily provide a single-phase sample with no impurities. M partially replaces the Ln sites, and is not the same rare earth element as Ln.

In complex oxide 1 represented by the formula Ln_(1-x)M_(x)NiO_(y), x is a value of not less than 0 and not more than 0.8 and y is a value of not less than 2.7 and not more than 3.3.

In complex oxide 2 represented by the formula (Ln_(1-x)M_(x))₂NiO_(y), x is a value of not less than 0 and not more than 0.8 and y is a value of not less than 3.6 and not more than 4.4.

Complex oxides 1 and 2 have a negative Seebeck coefficient and exhibit properties as n-type thermoelectric materials in that when a difference in temperature is created between both ends of the oxide material, the electric potential generated by the thermoelectromotive force is higher at the high-temperature side than at the low-temperature side. More specifically, complex oxides 1 and 2 have a negative Seebeck coefficient at 100° C. or higher.

Furthermore, complex oxides 1 and 2 have good electrical conductivity and low electrical resistivity, and more specifically, an electrical resistivity of 1 Ωcm or less at 100° C. or higher, in particular 100° C. to 700° C.

FIG. 1 shows an X-ray diffraction pattern of the complex oxide obtained in Example 1 given below, i.e., one embodiment of complex oxide 1. FIG. 1 also shows an X-ray diffraction pattern of the complex oxide obtained in Example 541 given below, i.e., one embodiment of complex oxide 2.

The X-ray diffraction patterns, although showing the presence of small amounts of impurities, clearly indicate that complex oxide 1 has a perovskite-type crystal structure and complex oxide 2 has a so-called layered perovskite-type structure, thus being a perovskite-related material.

FIG. 2 schematically shows the crystal structures of complex oxides 1 and 2. As shown in FIG. 2, complex oxide 1 has a perovskite-type ANiO₃ structure and complex oxide 2 has a layered perovskite-type A₂NiO₄ structure in both of which the A sites are occupied by Ln which may be partially substituted by M.

Complex oxides 1 and 2 can be prepared by mixing the starting materials in such a proportion so as to have the same metal component ratio as the desired complex oxide, followed by sintering. More specifically, the starting materials are mixed to have the same Ln/M/Ni metal component ratio as in the formula Ln_(1-x)M_(x)NiO_(y) or (Ln_(1-x)M_(x))₂NiO_(y), wherein Ln, M, x, and y are as defined above and the resulting mixture is sintered to provide the desired complex oxide.

The starting materials are not limited insofar as they can produce oxides when sintered. Examples of usable materials include metals, oxides, compounds (such as carbonates), and the like. Examples of usable sources of Nd include neodymium oxide (Nd₂O₃), neodymium carbonate (Nd₂(CO₃)₃), neodymium nitrate (Nd(NO₃)₃), neodymium chloride (NdCl₃), neodymium hydroxide (Nd(OH)₃), alkoxides, such as trimethoxy neodymium (Nd(OCH₃)₃), triethoxy neodymium (Nd(OC₂H₅)₃), tripropoxy neodymium (Nd(OC₃H₇)₃), etc.

Examples of usable sources of Ni are nickel oxide (NiO), nickel nitrate (Ni(NO₃)₂), nickel chloride (NiCl₂), nickel hydroxide (Ni(OH)₂), alkoxides such as dimethoxy nickel (Ni(OCH₃)₂), diethoxy nickel (Ni(OC₂H₅)₂) and dipropoxy nickel (Ni(OC₃H₇)₂), and the like. Similarly, examples of usable sources of other elements are oxides, chlorides, carbonates, nitrates, hydroxides, alkoxides and the like. Compounds containing two or more constituent elements of the complex oxide of the invention are also usable.

The sintering temperature and sintering time are not limited insofar as the desired complex oxide can be produced under such conditions. For example, the sintering may be performed at about 850° C. to about 1000° C. for about 20 to about 40 hours. When carbonates, organic compounds or the like are used as starting materials, the starting materials are preferably decomposed by calcination prior to sintering, and then sintered to give the desired complex oxide. For example, when carbonates are used as starting materials, they may be calcined at about 600° C. to about 800° C. for about 10 hours, and then sintered under the above-mentioned conditions.

Sintering means are not limited and any desired means such as electric furnaces and gas furnaces may be used. Usually, sintering may be conducted in an oxidizing atmosphere with a partial pressure of oxygen of about 1% or higher, such as in an oxygen stream or in air. When the starting materials contain a sufficient amount of oxygen, sintering in, for example, an inert atmosphere is also possible.

The amount of oxygen in a complex oxide to be produced can be controlled by adjusting the partial pressure of oxygen during sintering, sintering temperature, sintering time, etc. The higher the partial pressure of oxygen is, the higher the oxygen ratio in the above formulae can be.

The thus obtained complex oxides 1 and 2 of the invention have negative Seebeck coefficients and low electrical resistivities, i.e., an electrical resistivity of 1 Ωcm or less at 100° C. or higher, so that the oxides exhibit excellent thermoelectric conversion capabilities as n-type thermoelectric materials. Furthermore, the complex oxides have good heat resistance and chemical durability and are composed of elements of low toxicity and therefore highly practical as thermoelectric materials.

Complex oxides 1 and 2 of the invention with the above-mentioned properties can be effectively used as n-type thermoelectric materials in air at high temperatures.

FIG. 3 is a view schematically showing a thermoelectric module produced using a thermoelectric material comprising a complex oxide of the invention as its n-type thermoelectric elements. The thermoelectric module has a structure similar to conventional thermoelectric modules and comprises a high-temperature side substrate, a low-temperature side substrate, p-type thermoelectric materials, n-type thermoelectric materials, electrodes, and conductive wires. In such a module, the complex oxide of the invention is used as an n-type thermoelectric material.

The complex oxides of the invention have negative Seebeck coefficients and low electrical resistivities and also have excellent heat resistance, chemical durability, etc.

The complex oxides of the invention with such properties can be effectively utilized as n-type thermoelectric materials in air at high temperatures, whereas such use is impossible with conventional intermetallic compounds. Accordingly, by incorporating the complex oxides of the invention as n-type thermoelectric elements into thermoelectric system, it becomes possible to effectively utilize thermal energy conventionally lost to the atmosphere.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples are given below to illustrate the invention in further detail.

EXAMPLE 1

Using neodymium oxide (Nd₂O₃) as a source of Nd and nickel oxide (NiO) as a source of Ni, these starting materials were well mixed at a Nd:Ni ratio (element ratio) of 1.0:1.0. The mixture was molded by pressing, followed by sintering in an oxygen stream at 920° C. for 40 hours to prepare a complex oxide.

The complex oxide thus obtained had a composition represented by the formula NdNiO_(3.1).

FIG. 4 is a graph showing the temperature dependency of the Seebeck coefficient (S) of the obtained complex oxide over the temperature range of 100° C. to 700° C. It is apparent from FIG. 4 that the complex oxide has a negative Seebeck coefficient at 100° C. or higher, thus being confirmed to be an n-type thermoelectric material in which the high-temperature side has a high electric potential.

In all the Examples described below, the Seebeck coefficient at 100° C. or higher was negative.

FIG. 5 is a graph showing the temperature dependency of the electrical resistivity of the complex oxide. FIG. 5 demonstrates that the complex oxide shows a low electrical resistivity, i.e., an electrical resistivity of about 1 Ωcm or less over the temperature range of 100° C. to 700° C.

In all the Examples described below, the electrical resistivity was 1 Ωcm or less over the temperature range of 100° C. to 700° C.

EXAMPLES 2-1080

Starting materials were mixed at the element ratios shown in Tables 1 to 42, and the same procedure as in Example 1 was then conducted to provide complex oxides.

The sintering temperature was controlled within the range of 850° C. to 920° C. according to the desired complex oxide.

The complex oxides obtained in Examples 1 to 540 had a perovskite-type LnNiO₃ structure in which the Ln sites may be partially substituted by M, whereas those obtained in Examples 541 to 1080 had a layered perovskite-type Ln₂NiO₄ structure in which the Ln sites may be partially substituted by M.

Tables 1 to 42 below show the element ratios of the obtained complex oxides, their Seebeck coefficients at 700° C., and their electrical resistivities at 700° C.

With respect to the sintered complex oxide obtained in Example 541, the temperature dependency of the Seebeck coefficient (S) and the temperature dependency of the electrical resistivity over the temperature range of 100° C. to 700° C. are shown in FIG. 4 and FIG. 5, respectively. TABLE 1 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 1 Nd — 1:0:1:3.1 −8 18 2 Nd Na 0.99:0.01:1:2.9 −15 30 3 Nd Na 0.2:0.8:1:2.7 −8 43 4 Nd K 0.99:0.01:1:2.9 −10 14 5 Nd K 0.2:0.8:1:2.8 −12 40 6 Nd Li 0.99:0.01:1:3.0 −21 30 7 Nd Li 0.2:0.8:1:2.7 −5 45 8 Nd Zn 0.99:0.01:1:2.9 −3 27 9 Nd Zn 0.2:0.8:1:3.1 −12 24 10 Nd Pb 0.99:0.01:1:2.9 −10 14 11 Nd Pb 0.2:0.8:1:2.7 −18 20 12 Nd Ba 0.99:0.01:1:3.0 −10 19 13 Nd Ba 0.2:0.8:1:2.8 −8 19 14 Nd Ca 0.99:0.01:1:2.9 −8 30 15 Nd Ca 0.2:0.8:1:2.8 −9 24 16 Nd Al 0.99:0.01:1:3.3 −7 22 17 Nd Al 0.2:0.8:1:3.3 −8 30 18 Nd Bi 0.99:0.01:1:3.2 −10 41 19 Nd Bi 0.2:0.8:1:3.3 −8 29 20 Nd Y 0.99:0.01:1:2.9 −5 34 21 Nd Y 0.2:0.8:1:3.0 −10 27 22 Nd La 0.99:0.01:1:3.0 −20 32 23 Nd La 0.2:0.8:1:3.1 −15 19 24 Nd Ce 0.99:0.01:1:3.3 −8 30 25 Nd Ce 0.2:0.8:1:3.3 −4 42 26 Nd Pr 0.99:0.01:1:3.0 −11 28 27 Nd Pr 0.2:0.8:1:3.1 −17 24 28 Nd Sm 0.99:0.01:1:2.9 −5 27 29 Nd Sm 0.2:0.8:1:3.0 −10 31 30 Nd Eu 0.99:0.01:1:3.1 −8 45

TABLE 2 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 31 Nd Eu 0.2:0.8:1:3.2 −6 36 32 Nd Gd 0.99:0.01:1:2.9 −7 24 33 Nd Gd 0.2:0.8:1:3.0 −8 35 34 Nd Tb 0.99:0.01:1:2.8 −10 30 35 Nd Tb 0.2:0.8:1:3.0 −10 45 36 Nd Dy 0.99:0.01:1:2.9 −9 33 37 Nd Dy 0.2:0.8:1:3.1 −10 24 38 Nd Ho 0.99:0.01:1:3.1 −11 19 39 Nd Ho 0.2:0.8:1:3.3 −12 31 40 Nd Er 0.99:0.01:1:3.2 −18 45 41 Nd Er 0.2:0.8:1:3.3 −20 33 42 Nd Tm 0.99:0.01:1:3.0 −15 30 43 Nd Tm 0.2:0.8:1:3.0 −5 19 44 Nd Lu 0.99:0.01:1:3.1 −6 27 45 Nd Lu 0.2:0.8:1:3.2 −5 31 46 Ce — 1:0:1:3.1 −10 45 47 Ce Na 0.99:0.01:1:2.9 −10 36 48 Ce Na 0.2:0.8:1:2.7 −15 24 49 Ce K 0.99:0.01:1:2.8 −12 35 50 Ce K 0.2:0.8:1:2.8 −20 30 51 Ce Li 0.99:0.01:1:2.9 −7 45 52 Ce Li 0.2:0.8:1:2.7 −8 33 53 Ce Zn 0.99:0.01:1:3.1 −5 24 54 Ce Zn 0.2:0.8:1:3.3 −12 19 55 Ce Pb 0.99:0.01:1:2.9 −10 31 56 Ce Pb 0.2:0.8:1:2.8 −18 45 57 Ce Ba 0.99:0.01:1:2.9 −12 33

TABLE 3 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 58 Ce Ba 0.2:0.8:1:2.7 −6 30 59 Ce Ca 0.99:0.01:1:3.0 −8 19 60 Ce Ca 0.2:0.8:1:3.1 −5 31 61 Ce Al 0.99:0.01:1:3.3 −10 45 62 Ce Al 0.2:0.8:1:3.3 −8 36 63 Ce Bi 0.99:0.01:1:2.9 −4 24 64 Ce Bi 0.2:0.8:1:2.9 −10 35 65 Ce Y 0.99:0.01:1:2.9 −12 30 66 Ce Y 0.2:0.8:1:3.0 −8 45 67 Ce La 0.99:0.01:1:3.0 −6 47 68 Ce La 0.2:0.8:1:3.1 −4 18 69 Ce Pr 0.99:0.01:1:3.0 −11 30 70 Ce Pr 0.2:0.8:1:3.2 −4 43 71 Ce Nd 0.99:0.01:1:3.3 −8 14 72 Ce Nd 0.2:0.8:1:3.3 −9 40 73 Ce Sm 0.99:0.01:1:3.1 −15 30 74 Ce Sm 0.2:0.8:1:3.2 −17 45 75 Ce Eu 0.99:0.01:1:2.9 −8 27 76 Ce Eu 0.2:0.8:1:3.2 −7 24 77 Ce Gd 0.99:0.01:1:3.1 −6 14 78 Ce Gd 0.2:0.8:1:3.2 −18 20 79 Ce Tb 0.99:0.01:1:3.2 −8 19 80 Ce Tb 02:0.8:1:3.3 −20 19 81 Ce Dy 0.99:0.01:1:2.9 −15 30 82 Ce Dy 0.2:0.8:1:3.0 −12 24 83 Ce Ho 0.99:0.01:1:3.3 −8 22

TABLE 4 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 84 Ce Ho 0.2:0.8:1:3.2 −5 30 85 Ce Er 0.99:0.01:1:3.1 −5 41 86 Ce Er 0.2:0.8:1:3.2 −8 29 87 Ce Tm 0.99:0.01:1:2.9 −7 34 88 Ce Tm 0.2:0.8:1:3.3 −11 27 89 Ce Lu 0.99:0.01:1:3.1 −13 49 90 Ce Lu 0.2:0.8:1:3.2 −15 29 91 Pr — 1:0:1:3.1 −10 34 92 Pr Na 0.99:0.01:1:2.7 −12 27 93 Pr Na 0.2:0.8:1:2.9 −6 32 94 Pr K 0.99:0.01:1:3.0 −8 19 95 Pr K 0.2:0.8:1:2.9 −10 30 96 Pr Li 0.99:0.01:1:2.9 −12 42 97 Pr Li 0.2:0.8:1:2.7 −20 28 98 Pr Zn 0.99:0.01:1:3.1 −22 24 99 Pr Zn 0.2:0.8:1:3.3 −12 27 100 Pr Pb 0.99:0.01:1:2.9 −8 31 101 Pr Pb 0.2:0.8:1:2.7 −18 45 102 Pr Ba 0.99:0.01:1:3.0 −12 36 103 Pr Ba 0.2:0.8:1:2.7 −5 24 104 Pr Ca 0.99:0.01:1:2.9 −8 35 105 Pr Ca 0.2:0.8:1:2.7 −6 30 106 Pr Al 0.99:0.01:1:3.3 −9 45 107 Pr Al 0.2:0.8:1:3.3 −12 33 108 Pr Bi 0.99:0.01:1:3.3 −5 24 109 Pr Bi 0.2:0.8:1:3.3 −21 19

TABLE 5 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 110 Pr Y 0.99:0.01:1:3.0 −20 31 111 Pr Y 0.2:0.8:1:3.1 −5 45 112 Pr La 0.99:0.01:1:2.9 −8 33 113 Pr La 0.2:0.8:1:3.1 −12 30 114 Pr Ce 0.99:0.01:1:3.2 −20 19 115 Pr Ce 0.2:0.8:1:3.3 −8 27 116 Pr Nd 0.99:0.01:1:3.0 −5 31 117 Pr Nd 0.2:0.8:1:3.1 −8 45 118 Pr Sm 0.99:0.01:1:3.3 −10 36 119 Pr Sm 0.2:0.8:1:2.9 −6 24 120 Pr Eu 0.99:0.01:1:3.1 −6 35 121 Pr Eu 0.2:0.8:1:3.1 −8 30 122 Pr Gd 0.99:0.01:1:2.9 −12 45 123 Pr Gd 0.2:0.8:1:3.0 −10 33 124 Pr Tb 0.99:0.01:1:3.2 −8 24 125 Pr Tb 0.2:0.8:1:3.3 −6 19 126 Pr Dy 0.99:0.01:1:3.1 −12 31 127 Pr Dy 0.2:0.8:1:3.2 −13 33 128 Pr Ho 0.99:0.01:1:3.1 −8 30 129 Pr Ho 0.2:0.8:1:3.3 −9 19 130 Pr Er 0.99:0.01:1:2.9 −20 31 131 Pr Er 0.2:0.8:1:3.0 −5 45 132 Pr Tm 0.99:0.01:1:3.1 −12 36 133 Pr Tm 0.2:0.8:1:3.2 −11 24 134 Pr Lu 0.99:0.01:1:3.0 −6 35 135 Pr Lu 0.2:0.8:1:3.1 −12 30 136 Sm — 1:0:1:3.1 −10 45

TABLE 6 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 137 Sm Na 0.99:0.01:1:2.9 −15 47 138 Sm Na 0.2:0.8:1:2.7 −8 18 139 Sm K 0.99:0.01:1:2.9 −10 30 140 Sm K 0.2:0.8:1:2.8 −12 43 141 Sm Li 0.99:0.01:1:3.0 −21 14 142 Sm Li 0.2:0.8:1:2.7 −5 40 143 Sm Zn 0.99:0.01:1:2.9 −3 30 144 Sm Zn 0.2:0.8:1:3.1 −12 45 145 Sm Pb 0.99:0.01:1:2.9 −10 27 146 Sm Pb 0.2:0.8:1:2.7 −18 24 147 Sm Ba 0.99:0.01:1:3.0 −10 14 148 Sm Ba 0.2:0.8:1:2.8 −8 20 149 Sm Ca 0.99:0.01:1:2.9 −8 19 150 Sm Ca 0.2:0.8:1:2.8 −9 19 151 Sm Al 0.99:0.01:1:3.3 −7 30 152 Sm Al 0.2:0.8:1:3.3 −8 24 153 Sm Bi 0.99:0.01:1:3.2 −10 22 154 Sm Bi 0.2:0.8:1:3.3 −8 30 155 Sm Y 0.99:0.01:1:2.9 −5 41 156 Sm Y 0.2:0.8:1:3.0 −10 29 157 Sm La 0.99:0.01:1:3.0 −20 34 158 Sm La 0.2:0.8:1:3.1 −15 27 159 Sm La 0.99:0.01:1:3.3 −8 49 160 Sm Ce 0.2:0.8:1:3.3 −4 33 161 Sm Pr 0.99:0.01:1:3.0 −11 30 162 Sm Pr 0.2:0.8:1:3.1 −17 19

TABLE 7 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 163 Sm Nd 0.99:0.01:1:2.9 −5 62 164 Sm Nd 0.2:0.8:1:3.0 −10 71 165 Sm Eu 0.99:0.01:1:3.1 −8 45 166 Sm Eu 0.2:0.8:1:3.2 −6 31 167 Sm Gd 0.99:0.01:1:2.9 −7 45 168 Sm Gd 0.2:0.8:1:3.0 −8 36 169 Sm Tb 0.99:0.01:1:2.8 −10 24 170 Sm Tb 0.2:0.8:1:3.0 −10 35 171 Sm Dy 0.99:0.01:1:2.9 −9 30 172 Sm Dy 0.2:0.8:1:3.1 −10 45 173 Sm Ho 0.99:0.01:1:3.1 −11 33 174 Sm Ho 0.2:0.8:1:3.3 −12 24 175 Sm Er 0.99:0.01:1:3.2 −18 19 176 Sm Er 0.2:0.8:1:3.3 −20 31 177 Sm Tm 0.99:0.01:1:3.0 −15 45 178 Sm Tm 0.2:0.8:1:3.0 −5 33 179 Sm Lu 0.99:0.01:1:3.1 −6 30 180 Sm Lu 0.2:0.8:1:3.2 −5 19 181 Eu — 1:0:1:3.1 −10 27 182 Eu Na 0.99:0.01:1:2.7 −12 31 183 Eu Na 0.2:0.8:1:2.9 −6 45 184 Eu K 0.99:0.01:1:3.0 −8 36 185 Eu K 0.2:0.8:1:2.9 −10 24 186 Eu Li 0.99:0.01:1:2.9 −12 35 187 Eu Li 0.2:0.8:1:2.7 −20 30 188 Eu Zn 0.99:0.01:1:3.1 −22 45 189 Eu Zn 0.2:0.8:1:3.3 −12 33

TABLE 8 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 190 Eu Pb 0.99:0.01:1:2.9 −8 24 191 Eu Pb 0.2:0.8:1:2.7 −18 19 192 Eu Ba 0.99:0.01:1:3.0 −12 31 193 Eu Ba 0.2:0.8:1:2.7 −5 45 194 Eu Ca 0.99:0.01:1:2.9 −8 33 195 Eu Ca 0.2:0.8:1:2.7 −6 30 196 Eu Al 0.99:0.01:1:3.3 −9 19 197 Eu Al 0.2:0.8:1:3.3 −12 31 198 Eu Bi 0.99:0.01:1:3.3 −5 30 199 Eu Bi 0.2:0.8:1:3.3 −21 45 200 Eu Y 0.99:0.01:1:3.0 −20 33 201 Eu Y 0.2:0.8:1:3.1 −5 24 202 Eu La 0.99:0.01:1:2.9 −8 19 203 Eu La 0.2:0.8:1:3.1 −12 31 204 Eu Ce 0.99:0.01:1:3.2 −20 33 205 Eu Ce 0.2:0.8:1:3.3 −8 30 206 Eu Pr 0.99:0.01:1:3.0 −5 19 207 Eu Pr 0.2:0.8:1:3.1 −8 31 208 Eu Nd 0.99:0.01:1:3.3 −10 45 209 Eu Nd 0.2:0.8:1:2.9 −6 36 210 Eu Sm 0.99:0.01:1:3.1 −6 24 211 Eu Sm 0.2:0.8:1:3.1 −8 35 212 Eu Gd 0.99:0.01:1:2.9 −12 30 213 Eu Gd 0.2:0.8:1:3.0 −10 45 214 Eu Tb 0.99:0.01:1:3.2 −8 47 215 Eu Tb 0.2:0.8:1:3.3 −6 18

TABLE 9 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 216 Eu Dy 0.99:0.01:1:3.1 −12 30 217 Eu Dy 0.2:0.8:1:3.2 −13 43 218 Eu Ho 0.99:0.01:1:3.1 −8 14 219 Eu Ho 0.2:0.8:1:3.3 −9 40 220 Eu Er 0.99:0.01:1:2.9 −20 30 221 Eu Er 0.2:0.8:1:3.0 −5 45 222 Eu Tm 0.99:0.01:1:3.1 −12 27 223 Eu Tm 0.2:0.8:1:3.2 −11 24 224 Eu Lu 0.99:0.01:1:3.0 −6 14 225 Eu Lu 0.2:0.8:1:3.1 −12 20 226 Gd — 1:0:1:3.1 −10 19 227 Gd Na 0.99:0.01:1:2.9 −10 19 228 Gd Na 0.2:0.8:1:2.7 −15 30 229 Gd K 0.99:0.01:1:2.9 −12 24 230 Gd K 0.2:0.8:1:2.8 −20 22 231 Gd Li 0.99:0.01:1:3.0 −7 30 232 Gd Li 0.2:0.8:1:2.7 −8 41 233 Gd Zn 0.99:0.01:1:2.9 −5 30 234 Gd Zn 0.2:0.8:1:3.1 −12 45 235 Gd Pb 0.99:0.01:1:2.9 −10 33 236 Gd Pb 0.2:0.8:1:2.7 −18 24 237 Gd Ba 0.99:0.01:1:3.0 −12 90 238 Gd Ba 0.2:0.8:1:2.8 −6 72 239 Gd Ca 0.99:0.01:1:2.9 −8 45 240 Gd Ca 0.2:0.8:1:2.8 −5 30 241 Gd Al 0.99:0.01:1:3.3 −10 41 242 Gd Al 0.2:0.8:1:3.3 −8 29

TABLE 10 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 243 Gd Bi 0.99:0.01:1:3.2 −4 34 244 Gd Bi 0.2:0.8:1:3.3 −10 27 245 Gd Y 0.99:0.01:1:2.9 −12 49 246 Gd Y 0.2:0.8:1:3.0 −8 33 247 Gd La 0.99:0.01:1:3.0 −6 30 248 Gd La 0.2:0.8:1:3.1 −4 19 249 Gd Ce 0.99:0.01:1:3.3 −11 36 250 Gd Ce 0.2:0.8:1:3.3 −4 24 251 Gd Pr 0.99:0.01:1:3.0 −8 35 252 Gd Pr 0.2:0.8:1:3.1 −9 31 253 Gd Nd 0.99:0.01:1:2.9 −15 45 254 Gd Nd 0.2:0.8:1:3.0 −17 36 255 Gd Sm 0.99:0.01:1:3.1 −8 24 256 Gd Sm 0.2:0.8:1:3.2 −7 35 257 Gd Eu 0.99:0.01:1:2.9 −6 30 258 Gd Eu 0.2:0.8:1:3.0 −18 45 259 Gd Tb 0.99:0.01:1:2.8 −8 33 260 Gd Tb 0.2:0.8:1:3.0 −20 24 261 Gd Dy 0.99:0.01:1:2.9 −15 19 262 Gd Dy 0.2:0.8:1:3.1 −12 31 263 Gd Ho 0.99:0.01:1:3.1 −8 45 264 Gd Ho 0.2:0.8:1:3.3 −5 33 265 Gd Er 0.99:0.01:1:3.2 −5 30 266 Gd Er 0.2:0.8:1:3.3 −8 19 267 Gd Tm 0.99:0.01:1:3.0 −7 27 268 Gd Tm 0.2:0.8:1:3.0 −11 31

TABLE 11 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 269 Gd Lu 0.99:0.01:1:3.1 −13 45 270 Gd Lu 0.2:0.8:1:3.2 −15 36 271 Tb — 1:0:1:3.1 −10 24 272 Tb Na 0.99:0.01:1:2.9 −10 35 273 Tb Na 0.2:0.8:1:2.7 −15 30 274 Tb K 0.99:0.01:1:2.8 −12 45 275 Tb K 0.2:0.8:1:2.8 −20 33 276 Tb Li 0.99:0.01:1:2.9 −7 24 277 Tb Li 0.2:0.8:1:2.7 −8 19 278 Tb Zn 0.99:0.01:1:3.1 −5 31 279 Tb Zn 0.2:0.8:1:3.3 −12 45 280 Tb Pb 0.99:0.01:1:2.9 −10 33 281 Tb Pb 0.2:0.8:1:2.8 −18 30 282 Tb Ba 0.99:0.01:1:2.9 −12 19 283 Tb Ba 0.2:0.8:1:2.7 −6 31 284 Tb Ca 0.99:0.01:1:3.0 −8 30 285 Tb Ca 0.2:0.8:1:3.1 −5 45 286 Tb Al 0.99:0.01:1:3.3 −10 33 287 Tb Al 0.2:0.8:1:3.3 −8 24 288 Tb Bi 0.99:0.01:1:2.9 −4 19 289 Tb Bi 0.2:0.8:1:2.9 −10 31 290 Tb Y 0.99:0.01:1:2.9 −12 50 291 Tb Y 0.2:0.8:1:3.0 −8 33 292 Tb La 0.99:0.01:1:3.0 −6 49 293 Tb La 0.2:0.8:1:3.1 −4 14 294 Tb Ce 0.99:0.01:1:3.0 −11 20

TABLE 12 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 295 Tb Ce 0.2:0.8:1:3.2 −4 19 296 Tb Pr 0.99:0.01:1:3.3 −8 19 297 Tb Pr 0.2:0.8:1:3.3 −9 30 298 Tb Nd 0.99:0.01:1:3.1 −15 24 299 Tb Nd 0.2:0.8:1:3.2 −17 22 300 Tb Sm 0.99:0.01:1:2.9 −8 30 301 Tb Sm 0.2:0.8:1:3.2 −7 41 302 Tb Eu 0.99:0.01:1:3.1 −6 29 303 Tb Eu 0.2:0.8:1:3.2 −18 34 304 Tb Gd 0.99:0.01:1:3.2 −8 27 305 Tb Gd 0.2:0.8:1:3.3 −20 49 306 Tb Dy 0.99:0.01:1:2.9 −15 29 307 Tb Dy 0.2:0.8:1:3.0 −12 34 308 Tb Ho 0.99:0.01:1:3.3 −8 27 309 Tb Ho 0.2:0.8:1:3.2 −5 32 310 Tb Er 0.99:0.01:1:3.1 −5 19 311 Tb Er 0.2:0.8:1:3.2 −8 30 312 Tb Tm 0.99:0.01:1:2.9 −7 42 313 Tb Tm 0.2:0.8:1:3.3 −11 28 314 Tb Lu 0.99:0.01:1:3.1 −13 24 315 Tb Lu 0.2:0.8:1:3.2 −15 27 316 Dy — 1:0:1:3.1 −10 31 317 Dy Na 0.99:0.01:1:2.7 −15 45 318 Dy Na 0.2:0.8:1:2.9 −8 36 319 Dy K 0.99:0.01:1:3.0 −10 24 320 Dy K 0.2:0.8:1:2.9 −12 35

TABLE 13 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 321 Dy Li 0.99:0.01:1:2.9 −21 30 322 Dy Li 0.2:0.8:1:2.7 −5 45 323 Dy Zn 0.99:0.01:1:3.1 −3 33 324 Dy Zn 0.2:0.8:1:3.3 −12 24 325 Dy Pb 0.99:0.01:1:2.9 −10 19 326 Dy Pb 0.2:0.8:1:2.7 −18 31 327 Dy Ba 0.99:0.01:1:3.0 −10 45 328 Dy Ba 0.2:0.8:1:2.7 −8 33 329 Dy Ca 0.99:0.01:1:2.9 −8 30 330 Dy Ca 0.2:0.8:1:2.7 −9 19 331 Dy Al 0.99:0.01:1:3.3 −7 27 332 Dy Al 0.2:0.8:1:3.3 −8 14 333 Dy Bi 0.99:0.01:1:3.3 −10 20 334 Dy Bi 0.2:0.8:1:3.3 −8 19 335 Dy Y 0.99:0.01:1:3.0 −5 19 336 Dy Y 0.2:0.8:1:3.1 −10 30 337 Dy La 0.99:0.01:1:2.9 −20 24 338 Dy La 0.2:0.8:1:3.1 −15 22 339 Dy Ce 0.99:0.01:1:3.2 −8 30 340 Dy Ce 0.2:0.8:1:3.3 −4 41 341 Dy Pr 0.99:0.01:1:3.0 −11 29 342 Dy Pr 0.2:0.8:1:3.1 −17 34 343 Dy Nd 0.99:0.01:1:3.3 −5 27 344 Dy Nd 0.2:0.8:1:2.9 −10 49 345 Dy Sm 0.99:0.01:1:3.1 −8 29 346 Dy Sm 0.2:0.8:1:3.1 −6 34

TABLE 14 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 347 Dy Eu 0.99:0.01:1:2.9 −7 27 348 Dy Eu 0.2:0.8:1:3.0 −8 32 349 Dy Gd 0.99:0.01:1:3.2 −10 19 350 Dy Gd 0.2:0.8:1:3.3 −10 49 351 Dy Tb 0.99:0.01:1:3.1 −9 45 352 Dy Tb 0.2:0.8:1:3.2 −10 33 353 Dy Ho 0.99:0.01:1:3.1 −11 24 354 Dy Ho 0.2:0.8:1:3.3 −12 19 355 Dy Er 0.99:0.01:1:2.9 −18 31 356 Dy Er 0.2:0.8:1:3.0 −20 45 357 Dy Tm 0.99:0.01:1:3.1 −15 33 358 Dy Tm 0.2:0.8:1:3.2 −5 30 359 Dy Lu 0.99:0.01:1:3.0 −6 19 360 Dy Lu 0.2:0.8:1:3.1 −5 27 361 Ho — 1:0:1:3.1 −10 31 362 Ho Na 0.99:0.01:1:2.7 −12 45 363 Ho Na 0.2:0.8:1:2.9 −6 36 364 Ho K 0.99:0.01:1:3.0 −8 24 365 Ho K 0.2:0.8:1:2.9 −10 35 366 Ho Li 0.99:0.01:1:2.9 −12 30 367 Ho Li 0.2:0.8:1:2.7 −20 45 368 Ho Zn 0.99:0.01:1:3.1 −22 33 369 Ho Zn 0.2:0.8:1:3.3 −12 24 370 Ho Pb 0.99:0.01:1:2.9 −8 19 371 Ho Pb 0.2:0.8:1:2.7 −18 31 372 Ho Ba 0.99:0.01:1:3.0 −12 45

TABLE 15 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 373 Ho Ba 0.2:0.8:1:2.7 −5 33 374 Ho Ca 0.99:0.01:1:2.9 −8 30 375 Ho Ca 0.2:0.8:1:2.7 −6 19 376 Ho Al 0.99:0.01:1:3.3 −9 32 377 Ho Al 0.2:0.8:1:3.3 −12 50 378 Ho Bi 0.99:0.01:1:3.3 −5 15 379 Ho Bi 0.2:0.8:1:3.3 −21 27 380 Ho Y 0.99:0.01:1:3.0 −20 49 381 Ho Y 0.2:0.8:1:3.1 −5 29 382 Ho La 0.99:0.01:1:2.9 −8 58 383 Ho La 0.2:0.8:1:3.1 −12 35 384 Ho Ce 0.99:0.01:1:3.2 −20 40 385 Ho Ce 0.2:0.8:1:3.3 −8 27 386 Ho Pr 0.99:0.01:1:3.0 −5 49 387 Ho Pr 0.2:0.8:1:3.1 −8 29 388 Ho Nd 0.99:0.01:1:3.3 −10 39 389 Ho Nd 0.2:0.8:1:2.9 −6 14 390 Ho Sm 0.99:0.01:1:3.1 −6 20 391 Ho Sm 0.2:0.8:1:3.1 −8 19 392 Ho Eu 0.99:0.01:1:2.9 −12 19 393 Ho Eu 0.2:0.8:1:3.0 −10 30 394 Ho Gd 0.99:0.01:1:3.2 −8 24 395 Ho Gd 0.2:0.8:1:3.3 −6 22 396 Ho Tb 0.99:0.01:1:3.1 −12 30 397 Ho Tb 0.2:0.8:1:3.2 −13 41 398 Ho Dy 0.99:0.01:1:3.1 −8 29

TABLE 16 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 399 Ho Dy 0.2:0.8:1:3.3 −9 34 400 Ho Er 0.99:0.01:1:2.9 −20 27 401 Ho Er 0.2:0.8:1:3.0 −5 49 402 Ho Tm 0.99:0.01:1:3.1 −12 29 403 Ho Tm 0.2:0.8:1:3.2 −11 34 404 Ho Lu 0.99:0.01:1:3.0 −6 27 405 Ho Lu 0.2:0.8:1:3.1 −12 32 406 Er — 1:0:1:3.1 −10 19 407 Er Na 0.99:0.01:1:2.9 −15 30 408 Er Na 0.2:0.8:1:2.7 −8 42 409 Er K 0.99:0.01:1:2.9 −10 28 410 Er K 0.2:0.8:1:2.8 −12 24 411 Er Li 0.99:0.01:1:3.0 −21 27 412 Er Li 0.2:0.8:1:2.7 −5 31 413 Er Zn 0.99:0.01:1:2.9 −3 45 414 Er Zn 0.2:0.8:1:3.1 −12 36 415 Er Pb 0.99:0.01:1:2.9 −10 24 416 Er Pb 0.2:0.8:1:2.7 −18 35 417 Er Ba 0.99:0.01:1:3.0 −10 30 418 Er Ba 0.2:0.8:1:2.8 −8 45 419 Er Ca 0.99:0.01:1:2.9 −8 33 420 Er Ca 0.2:0.8:1:2.8 −9 24 421 Er Al 0.99:0.01:1:3.3 −7 19 422 Er Al 0.2:0.8:1:3.3 −8 31 423 Er Bi 0.99:0.01:1:3.2 −10 45 424 Er Bi 0.2:0.8:1:3.3 −8 30

TABLE 17 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 425 Er Y 0.99:0.01:1:2.9 −5 19 426 Er Y 0.2:0.8:1:3.0 −10 27 427 Er La 0.99:0.01:1:3.0 −20 31 428 Er La 0.2:0.8:1:3.1 −15 45 429 Er Ce 0.99:0.01:1:3.3 −8 36 430 Er Ce 0.2:0.8:1:3.3 −4 24 431 Er Pr 0.99:0.01:1:3.0 −11 35 432 Er Pr 0.2:0.8:1:3.1 −17 30 433 Er Nd 0.99:0.01:1:2.9 −5 45 434 Er Nd 0.2:0.8:1:3.0 −10 33 435 Er Sm 0.99:0.01:1:3.1 −8 24 436 Er Sm 0.2:0.8:1:3.2 −6 19 437 Er Eu 0.99:0.01:1:2.9 −7 31 438 Er Eu 0.2:0.8:1:3.0 −8 45 439 Er Gd 0.99:0.01:1:2.8 −10 33 440 Er Gd 0.2:0.8:1:3.0 −10 30 441 Er Tb 0.99:0.01:1:2.9 −9 19 442 Er Tb 0.2:0.8:1:3.1 −10 27 443 Er Dy 0.99:0.01:1:3.1 −11 49 444 Er Dy 0.2:0.8:1:3.3 −12 29 445 Er Ho 0.99:0.01:1:3.2 −18 34 446 Er Ho 0.2:0.8:1:3.3 −20 27 447 Er Tm 0.99:0.01:1:3.0 −15 32 448 Er Tm 0.2:0.8:1:3.0 −5 19 449 Er Lu 0.99:0.01:1:3.1 −6 49 450 Er Lu 0.2:0.8:1:3.2 −5 45

TABLE 18 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 451 Tm — 1:0:1:3.1 −10 33 452 Tm Na 0.99:0.01:1:2.9 −10 24 453 Tm Na 0.2:0.8:1:2.7 −15 19 454 Tm K 0.99:0.01:1:2.8 −12 31 455 Tm K 0.2:0.8:1:2.8 −20 45 456 Tm Li 0.99:0.01:1:2.9 −7 75 457 Tm Li 0.2:0.8:1:2.7 −8 55 458 Tm Zn 0.99:0.01:1:3.1 −5 19 459 Tm Zn 0.2:0.8:1:3.3 −12 31 460 Tm Pb 0.99:0.01:1:2.9 −10 45 461 Tm Pb 0.2:0.8:1:2.8 −18 30 462 Tm Ba 0.99:0.01:1:2.9 −12 19 463 Tm Ba 0.2:0.8:1:2.7 −6 27 464 Tm Ca 0.99:0.01:1:3.0 −8 31 465 Tm Ca 0.2:0.8:1:3.1 −5 45 466 Tm Al 0.99:0.01:1:3.3 −10 36 467 Tm Al 0.2:0.8:1:3.3 −8 24 468 Tm Bi 0.99:0.01:1:2.9 −4 35 469 Tm Bi 0.2:0.8:1:2.9 −10 30 470 Tm Y 0.99:0.01:1:2.9 −12 45 471 Tm Y 0.2:0.8:1:3.0 −8 33 472 Tm La 0.99:0.01:1:3.0 −6 58 473 Tm La 0.2:0.8:1:3.1 −4 35 474 Tm Ce 0.99:0.01:1:3.0 −11 40 475 Tm Ce 0.2:0.8:1:3.2 −4 30 476 Tm Pr 0.99:0.01:1:3.3 −8 19

TABLE 19 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mO cm) 477 Tm Pr 0.2:0.8:1:3.3 −9 27 478 Tm Nd 0.99:0.01:1:3.1 −15 31 479 Tm Nd 0.2:0.8:1:3.2 −17 45 480 Tm Sm 0.99:0.01:1:2.9 −8 36 481 Tm Sm 0.2:0.8:1:3.2 −7 24 482 Tm Eu 0.99:0.01:1:3.1 −6 35 483 Tm Eu 0.2:0.8:1:3.2 −18 30 484 Tm Gd 0.99:0.01:1:3.2 −8 45 485 Tm Gd 0.2:0.8:1:3.3 −20 33 486 Tm Tb 0.99:0.01:1:2.9 −15 24 487 Tm Tb 0.2:0.8:1:3.0 −12 19 488 Tm Dy 0.99:0.01:1:3.3 −8 31 489 Tm Dy 0.2:0.8:1:3.2 −5 45 490 Tm Ho 0.99:0.01:1:3.1 −5 33 491 Tm Ho 0.2:0.8:1:3.2 −8 30 492 Tm Er 0.99:0.01:1:2.9 −7 19 493 Tm Er 0.2:0.8:1:3.3 −11 27 494 Tm Lu 0.99:0.01:1:3.1 −13 35 495 Tm Lu 0.2:0.8:1:3.2 −15 40 496 Lu — 1:0:1:3.1 −10 30 497 Lu Na 0.99:0.01:1:2.7 −12 19 498 Lu Na 0.2:0.8:1:2.9 −6 27 499 Lu K 0.99:0.01:1:3.0 −8 31 500 Lu K 0.2:0.8:1:2.9 −10 45 501 Lu Li 0.99:0.01:1:2.9 −12 35 502 Lu Li 0.2:0.8:1:2.7 −20 40

TABLE 20 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 503 Lu Zn 0.99:0.01:1:3.1 −22 30 504 Lu Zn 0.2:0.8:1:3.3 −12 19 505 Lu Pb 0.99:0.01:1:2.9 −8 27 506 Lu Pb 0.2:0.8:1:2.7 −18 31 507 Lu Ba 0.99:0.01:1:3.0 −12 45 508 Lu Ba 0.2:0.8:1:2.7 −5 36 509 Lu Ca 0.99:0.01:1:2.9 −8 24 510 Lu Ca 0.2:0.8:1:2.7 −6 35 511 Lu Al 0.99:0.01:1:3.3 −9 30 512 Lu Al 0.2:0.8:1:3.3 −12 45 513 Lu Bi 0.99:0.01:1:3.3 −5 33 514 Lu Bi 0.2:0.8:1:3.3 −21 35 515 Lu Y 0.99:0.01:1:3.0 −20 40 516 Lu Y 0.2:0.8:1:3.1 −5 30 517 Lu La 0.99:0.01:1:2.9 −8 19 518 Lu La 0.2:0.8:1:3.1 −12 27 519 Lu Ce 0.99:0.01:1:3.2 −20 31 520 Lu Ce 0.2:0.8:1:3.3 −8 45 521 Lu Pr 0.99:0.01:1:3.0 −5 36 522 Lu Pr 0.2:0.8:1:3.1 −8 24 523 Lu Nd 0.99:0.01:1:3.3 −10 35 524 Lu Nd 0.2:0.8:1:2.9 −6 30 525 Lu Sm 0.99:0.01:1:3.1 −6 45 526 Lu Sm 0.2:0.8:1:3.1 −8 33 527 Lu Eu 0.99:0.01:1:2.9 −12 35 528 Lu Eu 0.2:0.8:1:3.0 −10 40

TABLE 21 Ln_(1−x)M_(x)NiO_(y) Seebeck Electrical coefficient resistivity at 700° C. at 700° C. No. Ln M Ln:M:Ni:O (μVK⁻¹) (mΩcm) 529 Lu Gd 0.99:0.01:1:3.2 −8 30 530 Lu Gd 0.2:0.8:1:3.3 −6 49 531 Lu Tb 0.99:0.01:1:3.1 −12 31 532 Lu Tb 0.2:0.8:1:3.2 −13 45 533 Lu Dy 0.99:0.01:1:3.1 −8 75 534 Lu Dy 0.2:0.8:1:3.3 −9 55 535 Lu Ho 0.99:0.01:1:2.9 −20 19 536 Lu Ho 0.2:0.8:1:3.0 −5 31 537 Lu Er 0.99:0.01:1:3.1 −12 45 538 Lu Er 0.2:0.8:1:3.2 −11 30 539 Lu Tm 0.99:0.01:1:3.0 −6 19 540 Lu Tm 0.2:0.8:1:3.1 −12 27

TABLE 22 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 541 Nd — 1:0:1:4.0 −6 25 542 Nd Na 0.99:0.01:1:3.6 −12 25 543 Nd Na 0.2:0.8:1:3.9 −20 38 544 Nd K 0.99:0.01:1:3.7 −22 34 545 Nd K 0.2:0.8:1:3.8 −12 24 546 Nd Li 0.99:0.01:1:3.8 −8 17 547 Nd Li 0.2:0.8:1:3.6 −18 35 548 Nd Zn 0.99:0.01:1:4.0 −12 38 549 Nd Zn 0.2:0.8:1:3.8 −5 44 550 Nd Pb 0.99:0.01:1:3.6 −8 36 551 Nd Pb 0.2:0.8:1:3.6 −6 30 552 Nd Ba 0.99:0.01:1:3.9 −9 42 553 Nd Ba 0.2:0.8:1:4.0 −12 28 554 Nd Ca 0.99:0.01:1:3.8 −5 24 555 Nd Ca 0.2:0.8:1:4.0 −21 27 556 Nd Al 0.99:0.01:1:4.0 −20 31 557 Nd Al 0.2:0.8:1:4.1 −5 45 558 Nd Bi 0.99:0.01:1:4.2 −15 36 559 Nd Bi 0.2:0.8:1:4.4 −8 24 560 Nd Y 0.99:0.01:1:4.2 −12 35 561 Nd Y 0.2:0.8:1:4.3 −10 30 562 Nd La 0.99:0.01:1:4.0 −19 45 563 Nd La 0.2:0.8:1:4.1 −8 33 564 Nd Ce 0.99:0.01:1:4.2 −5 24 565 Nd Ce 02:0.8:1:4.4 −8 19 566 Nd Pr 0.99:0.01:1:4.1 −10 31 567 Nd Pr 0.2:0.8:1:4.2 −6 45 568 Nd Sm 0.99:0.01:1:4.3 −6 33 569 Nd Sm 0.2:0.8:1:4.2 −8 30 570 Nd Eu 0.99:0.01:1:4.1 −12 19 571 Nd Eu 0.2:0.8:1:4.0 −10 27

TABLE 23 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 572 Nd Gd 0.99:0.01:1:3.9 −8 44 573 Nd Gd 0.2:0.8:1:4.1 −6 37 574 Nd Tb 0.99:0.01:1:4.0 −12 38 575 Nd Tb 0.2:0.8:1:3.9 −13 45 576 Nd Dy 0.99:0.01:1:4.2 −8 28 577 Nd Dy 0.2:0.8:1:4.1 −9 34 578 Nd Ho 0.99:0.01:1:4.2 −8 19 579 Nd Ho 0.2:0.8:1:4.3 −5 30 580 Nd Er 0.99:0.01:1:4.1 −8 22 581 Nd Er 0.2:0.8:1:4.2 −10 36 582 Nd Tm 0.99:0.01:1:4.0 −6 38 583 Nd Tm 0.2:0.8:1:4.1 −6 44 584 Nd Lu 0.99:0.01:1:4.2 −8 22 585 Nd Lu 0.2:0.8:1:4.3 −12 19 586 Ce — 1:0:1:4.1 −10 31 587 Ce Na 0.99:0.01:1:3.9 −8 29 588 Ce Na 0.2:0.8:1:3.8 −6 22 589 Ce K 0.99:0.01:1:3.8 −12 24 590 Ce K 0.2:0.8:1:4.0 −13 32 591 Ce Li 0.99:0.01:1:4.1 −8 29 592 Ce Li 0.2:0.8:1:3.9 −9 35 593 Ce Zn 0.99:0.01:1:4.2 −20 48 594 Ce Zn 0.2:0.8:1:4.0 −5 34 595 Ce Pb 0.99:0.01:1:4.0 −12 16 596 Ce Pb 0.2:0.8:1:3.9 −11 28 597 Ce Ba 0.99:0.01:1:3.9 −6 39 598 Ce Ba 0.2:0.8:1:4.0 −25 20

TABLE 24 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 599 Ce Ca 0.99:0.01:1:4.0 −18 14 600 Ce Ca 0.2:0.8:1:4.0 −21 22 601 Ce Al 0.99:0.01:1:3.9 −14 31 602 Ce Al 0.2:0.8:1:4.2 −18 44 603 Ce Bi 0.99:0.01:1:4.4 −8 35 604 Ce Bi 0.2:0.8:1:4.3 −5 30 605 Ce Y 0.99:0.01:1:4.0 −8 25 606 Ce Y 0.2:0.8:1:4.2 −10 33 607 Ce La 0.99:0.01:1:4.1 −6 34 608 Ce La 0.2:0.8:1:3.9 −6 40 609 Ce Pr 0.99:0.01:1:3.9 −8 26 610 Ce Pr 0.2:0.8:1:4.2 −12 38 611 Ce Nd 0.99:0.01:1:4.1 −10 23 612 Ce Nd 0.2:0.8:1:4.0 −8 32 613 Ce Sm 0.99:0.01:1:4.3 −6 15 614 Ce Sm 0.2:0.8:1:4.2 −12 25 615 Ce Eu 0.99:0.01:1:4.0 −13 44 616 Ce Eu 0.2:0.8:1:4.1 −8 22 617 Ce Gd 0.99:0.01:1:4.0 −9 30 618 Ce Gd 0.2:0.8:1:4.0 −20 45 619 Ce Tb 0.99:0.01:1:3.9 −5 23 620 Ce Tb 0.2:0.8:1:4.2 −18 16 621 Ce Dy 0.99:0.01:1:4.1 −8 26 622 Ce Dy 0.2:0.8:1:4.0 −5 30 623 Ce Ho 0.99:0.01:1:4.2 −8 22 624 Ce Ho 0.2:0.8:1:4.1 −5 19

TABLE 25 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 625 Ce Er 0.99:0.01:1:4.3 −8 24 626 Ce Er 0.2:0.8:1:3.9 −10 35 627 Ce Tm 0.99:0.01:1:4.0 −6 30 628 Ce Tm 0.2:0.8:1:4.2 −6 43 629 Ce Lu 0.99:0.01:1:4.1 −8 14 630 Ce Lu 0.2:0.8:1:4.2 −12 40 631 Pr — 1:0:1:4.1 −10 30 632 Pr Na 0.99:0.01:1:3.8 −8 45 633 Pr Na 0.2:0.8:1:3.9 −6 27 634 Pr K 0.99:0.01:1:3.6 −12 24 635 Pr K 0.2:0.8:1:3.9 −13 14 636 Pr Li 0.99:0.01:1:3.9 −8 20 637 Pr Li 0.2:0.8:1:3.8 −9 19 638 Pr Zn 0.99:0.01:1:4.1 −20 30 639 Pr Zn 0.2:0.8:1:4.0 −5 24 640 Pr Pb 0.99:0.01:1:3.8 −12 22 641 Pr Pb 0.2:0.8:1:4.0 −8 30 642 Pr Ba 0.99:0.01:1:4.0 −8 41 643 Pr Ba 0.2:0.8:1:4.0 −5 29 644 Pr Ca 0.99:0.01:1:3.9 −8 34 645 Pr Ca 0.2:0.8:1:3.9 −10 27 646 Pr Al 0.99:0.01:1:4.2 −6 32 647 Pr Al 0.2:0.8:1:4.1 −6 19 648 Pr Bi 0.99:0.01:1:4.3 −8 15 649 Pr Bi 0.2:0.8:1:4.4 −12 30 650 Pr Y 0.99:0.01:1:4.2 −10 27

TABLE 26 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 651 Pr Y 0.2:0.8:1:4.0 −8 24 652 Pr La 0.99:0.01:1:4.2 −6 39 653 Pr La 0.2:0.8:1:4.1 −12 29 654 Pr Ce 0.99:0.01:1:4.2 −13 30 655 Pr Ce 0.2:0.8:1:4.2 −8 45 656 Pr Nd 0.99:0.01:1:4.0 −9 36 657 Pr Nd 0.2:0.8:1:4.1 −20 24 658 Pr Sm 0.99:0.01:1:3.9 −5 22 659 Pr Sm 0.2:0.8:1:4.1 −18 20 660 Pr Eu 0.99:0.01:1:4.2 −8 34 661 Pr Eu 0.2:0.8:1:4.1 −5 25 662 Pr Gd 0.99:0.01:1:4.0 −8 39 663 Pr Gd 0.2:0.8:1:4.1 −6 25 664 Pr Tb 0.99:0.01:1:4.0 −12 29 665 Pr Tb 0.2:0.8:1:4.0 −16 22 666 Pr Dy 0.99:0.01:1:3.9 −25 24 667 Pr Dy 0.2:0.8:1:4.1 −18 32 668 Pr Ho 0.99:0.01:1:4.2 −5 29 669 Pr Ho 0.2:0.8:1:4.0 −8 35 670 Pr Er 0.99:0.01:1:4.2 −5 48 671 Pr Er 0.2:0.8:1:4.1 −8 34 672 Pr Tm 0.99:0.01:1:3.9 −10 16 673 Pr Tm 0.2:0.8:1:4.2 −6 28 674 Pr Lu 0.99:0.01:1:4.2 −18 39 675 Pr Lu 0.2:0.8:1:4.3 −20 20 676 Sm — 1:0:1:4.1 −19 14 677 Sm Na 0.99:0.01:1:3.9 −16 22

TABLE 27 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 678 Sm Na 0.2:0.8:1:3.8 −6 31 679 Sm K 0.99:0.01:1:3.8 −12 44 680 Sm K 0.2:0.8:1:4.0 −16 35 681 Sm Li 0.99:0.01:1:4.1 −25 30 682 Sm Li 0.2:0.8:1:3.9 −18 25 683 Sm Zn 0.99:0.01:1:4.2 −5 33 684 Sm Zn 0.2:0.8:1:4.0 −8 34 685 Sm Pb 0.99:0.01:1:4.0 −5 40 686 Sm Pb 0.2:0.8:1:3.9 −8 26 687 Sm Ba 0.99:0.01:1:3.9 −10 38 688 Sm Ba 0.2:0.8:1:4.0 −6 23 689 Sm Ca 0.99:0.01:1:4.0 −6 32 690 Sm Ca 0.2:0.8:1:4.0 −8 38 691 Sm Al 0.99:0.01:1:3.9 −12 44 692 Sm Al 0.2:0.8:1:4.2 −10 22 693 Sm Bi 0.99:0.01:1:4.4 −8 19 694 Sm Bi 0.2:0.8:1:4.3 −6 31 695 Sm Y 0.99:0.01:1:4.0 −12 29 696 Sm Y 0.2:0.8:1:4.2 −13 22 697 Sm La 0.99:0.01:1:4.1 −8 24 698 Sm La 0.2:0.8:1:3.9 −9 32 699 Sm Ce 0.99:0.01:1:3.9 −20 29 700 Sm Ce 0.2:0.8:1:4.2 −5 35 701 Sm Pr 0.99:0.01:1:4.1 −12 48 702 Sm Pr 0.2:0.8:1:4.0 −8 34 703 Sm Nd 0.99:0.01:1:4.3 −8 16

TABLE 28 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 704 Sm Nd 0.2:0.8:1:4.2 −12 28 705 Sm Eu 0.99:0.01:1:4.0 −24 39 706 Sm Eu 0.2:0.8:1:4.1 −17 20 707 Sm Gd 0.99:0.01:1:4.0 −5 14 708 Sm Gd 0.2:0.8:1:4.0 −8 22 709 Sm Tb 0.99:0.01:1:3.9 −5 31 710 Sm Tb 0.2:0.8:1:4.2 −8 44 711 Sm Dy 0.99:0.01:1:4.1 −10 35 712 Sm Dy 0.2:0.8:1:4.0 −6 30 713 Sm Ho 0.99:0.01:1:4.2 −6 25 714 Sm Ho 0.2:0.8:1:4.1 −8 33 715 Sm Er 0.99:0.01:1:4.3 −12 34 716 Sm Er 0.2:0.8:1:3.9 −10 40 717 Sm Tm 0.99:0.01:1:4.0 −8 26 718 Sm Tm 0.2:0.8:1:4.2 −6 19 719 Sm Lu 0.99:0.01:1:4.1 −12 15 720 Sm Lu 0.2:0.8:1:4.2 −13 30 721 Eu — 1:0:1:4.1 −8 27 722 Eu Na 0.99:0.01:1:3.8 −9 24 723 Eu Na 0.2:0.8:1:3.9 −20 39 724 Eu K 0.99:0.01:1:3.6 −5 29 725 Eu K 0.2:0.8:1:3.9 −12 30 726 Eu Li 0.99:0.01:1:3.9 −8 45 727 Eu Li 0.2:0.8:1:3.8 −8 36 728 Eu Zn 0.99:0.01:1:4.1 −5 24 729 Eu Zn 0.2:0.8:1:4.0 −8 22 730 Eu Pb 0.99:0.01:1:3.8 −10 20

TABLE 29 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 731 Eu Pb 0.2:0.8:1:4.0 −6 34 732 Eu Ba 0.99:0.01:1:4.0 −20 25 733 Eu Ba 0.2:0.8:1:4.0 −25 39 734 Eu Ca 0.99:0.01:1:3.9 −16 25 735 Eu Ca 0.2:0.8:1:3.9 −13 29 736 Eu Al 0.99:0.01:1:4.2 −8 22 737 Eu Al 0.2:0.8:1:4.1 −6 24 738 Eu Bi 0.99:0.01:1:4.3 −12 32 739 Eu Bi 0.2:0.8:1:4.4 −13 29 740 Eu Y 0.99:0.01:1:4.2 −8 35 741 Eu Y 0.2:0.8:1:4.0 −9 48 742 Eu La 0.99:0.01:1:4.2 −20 34 743 Eu La 0.2:0.8:1:4.1 −5 16 744 Eu Ce 0.99:0.01:1:4.2 −18 28 745 Eu Ce 0.2:0.8:1:4.2 −8 39 746 Eu Pr 0.99:0.01:1:4.0 −5 20 747 Eu Pr 0.2:0.8:1:4.1 −19 14 748 Eu Nd 0.99:0.01:1:3.9 −16 22 749 Eu Nd 0.2:0.8:1:4.1 −25 31 750 Eu Sm 0.99:0.01:1:4.2 −12 44 751 Eu Sm 0.2:0.8:1:4.1 −5 19 752 Eu Gd 0.99:0.01:1:4.0 −8 32 753 Eu Gd 0.2:0.8:1:4.1 −6 15 754 Eu Tb 0.99:0.01:1:4.0 −5 25 755 Eu Tb 0.2:0.8:1:4.0 −8 44 756 Eu Dy 0.99:0.01:1:3.9 −5 22

TABLE 30 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 757 Eu Dy 0.2:0.8:1:4.1 −8 30 758 Eu Ho 0.99:0.01:1:4.2 −10 45 759 Eu Ho 0.2:0.8:1:4.0 −6 23 760 Eu Er 0.99:0.01:1:4.2 −6 16 761 Eu Er 0.2:0.8:1:4.1 −8 26 762 Eu Tm 0.99:0.01:1:3.9 −12 30 763 Eu Tm 0.2:0.8:1:4.2 −10 22 764 Eu Lu 0.99:0.01:1:4.2 −8 19 765 Eu Lu 0.2:0.8:1:4.3 −6 24 766 Gd — 1:0:1:4.0 −12 35 767 Gd Na 0.99:0.01:1:3.6 −16 30 768 Gd Na 0.2:0.8:1:3.9 −25 43 769 Gd K 0.99:0.01:1:3.7 −18 14 770 Gd K 0.2:0.8:1:3.8 −5 40 771 Gd Li 0.99:0.01:1:3.8 −8 30 772 Gd Li 0.2:0.8:1:3.6 −5 45 773 Gd Zn 0.99:0.01:1:4.0 −8 27 774 Gd Zn 0.2:0.8:1:3.8 −10 24 775 Gd Pb 0.99:0.01:1:3.6 −6 14 776 Gd Pb 0.2:0.8:1:3.6 −6 20 777 Gd Ba 0.99:0.01:1:3.9 −8 19 778 Gd Ba 0.2:0.8:1:4.0 −12 30 779 Gd Ca 0.99:0.01:1:3.8 −10 24 780 Gd Ca 0.2:0.8:1:4.0 −8 22 781 Gd Al 0.99:0.01:1:4.0 −6 30 782 Gd Al 0.2:0.8:1:4.1 −12 41 783 Gd Bi 0.99:0.01:1:4.2 −13 29

TABLE 31 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 784 Gd Bi 0.2:0.8:1:4.4 −8 34 785 Gd Y 0.99:0.01:1:4.2 −9 27 786 Gd Y 0.2:0.8:1:4.3 −20 32 787 Gd La 0.99:0.01:1:4.0 −5 19 788 Gd La 0.2:0.8:1:4.1 −12 15 789 Gd Ce 0.99:0.01:1:4.2 −8 25 790 Gd Ce 0.2:0.8:1:4.4 −8 33 791 Gd Pr 0.99:0.01:1:4.1 −5 34 792 Gd Pr 0.2:0.8:1:4.2 −8 40 793 Gd Nd 0.99:0.01:1:4.3 −10 26 794 Gd Nd 0.2:0.8:1:4.2 −6 19 795 Gd Sm 0.99:0.01:1:4.1 −8 15 796 Gd Sm 0.2:0.8:1:4.0 −5 30 797 Gd Eu 0.99:0.01:1:3.9 −8 27 798 Gd Eu 0.2:0.8:1:4.1 −10 24 799 Gd Tb 0.99:0.01:1:4.0 −6 39 800 Gd Tb 0.2:0.8:1:3.9 −6 29 801 Gd Dy 0.99:0.01:1:4.2 −8 30 802 Gd Dy 0.2:0.8:1:4.1 −12 45 803 Gd Ho 0.99:0.01:1:4.2 −10 36 804 Gd Ho 0.2:0.8:1:4.3 −8 24 805 Gd Er 0.99:0.01:1:4.1 −6 22 806 Gd Er 0.2:0.8:1:4.2 −12 20 807 Gd Tm 0.99:0.01:1:4.0 −16 34 808 Gd Tm 0.2:0.8:1:4.1 −6 25 809 Gd Lu 0.99:0.01:1:4.2 −12 39

TABLE 32 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 810 Gd Lu 0.2:0.8:1:4.3 −16 25 811 Tb — 1:0:1:4.1 −25 29 812 Tb Na 0.99:0.01:1:3.9 −18 22 813 Tb Na 0.2:0.8:1:3.8 −5 24 814 Tb K 0.99:0.01:1:3.8 −8 32 815 Tb K 0.2:0.8:1:4.0 −5 29 816 Tb Li 0.99:0.01:1:4.1 −8 35 817 Tb Li 0.2:0.8:1:3.9 −10 48 818 Tb Zn 0.99:0.01:1:42 −6 34 819 Tb Zn 0.2:0.8:1:4.0 −6 16 820 Tb Pb 0.99:0.01:1:4.0 −8 28 821 Tb Pb 0.2:0.8:1:3.9 −12 39 822 Tb Ba 0.99:0.01:1:3.9 −10 20 823 Tb Ba 0.2:0.8:1:4.0 −8 14 824 Tb Ca 0.99:0.01:1:4.0 −8 22 825 Tb Ca 0.2:0.8:1:4.0 −23 31 826 Tb Al 0.99:0.01:1:3.9 −27 44 827 Tb Al 0.2:0.8:1:4.2 −18 19 828 Tb Bi 0.99:0.01:1:4.4 −15 32 829 Tb Bi 0.2:0.8:1:4.3 −8 15 830 Tb Y 0.99:0.01:1:4.0 −12 26 831 Tb Y 0.2:0.8:1:4.2 −10 30 832 Tb La 0.99:0.01:1:4.1 −19 22 833 Tb La 0.2:0.8:1:3.9 −25 19 834 Tb Ce 0.99:0.01:1:3.9 −14 24 835 Tb Ce 0.2:0.8:1:4.2 −12 35

TABLE 33 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 836 Tb Pr 0.99:0.01:1:4.1 −5 30 837 Tb Pr 0.2:0.8:1:4.0 −8 43 838 Tb Nd 0.99:0.01:1:4.3 −6 14 839 Tb Nd 0.2:0.8:1:4.2 −9 40 840 Tb Sm 0.99:0.01:1:4.0 −12 30 841 Tb Sm 0.2:0.8:1:4.1 −5 45 842 Tb Eu 0.99:0.01:1:4.0 −21 27 843 Tb Eu 0.2:0.8:1:4.0 −20 24 844 Tb Gd 0.99:0.01:1:3.9 −5 14 845 Tb Gd 0.2:0.8:1:4.2 −8 20 846 Tb Dy 0.99:0.01:1:4.1 −12 19 847 Tb Dy 0.2:0.8:1:4.0 −20 30 848 Tb Ho 0.99:0.01:1:4.2 −8 24 849 Tb Ho 0.2:0.8:1:4.1 −5 22 850 Tb Er 0.99:0.01:1:4.3 −8 30 851 Tb Er 0.2:0.8:1:3.9 −10 41 852 Tb Tm 0.99:0.01:1:4.0 −6 29 853 Tb Tm 0.2:0.8:1:4.2 −6 34 854 Tb Lu 0.99:0.01:1:4.1 −8 27 855 Tb Lu 0.2:0.8:1:4.2 −18 32 856 Dy — 1:0:1:4.0 −20 19 857 Dy Na 0.99:0.01:1:3.6 −18 15 858 Dy Na 0.2:0.8:1:3.9 −5 25 859 Dy K 0.99:0.01:1:3.7 −8 30 860 Dy K 0.2:0.8:1:3.8 −6 43 861 Dy Li 0.99:0.01:1:3.8 −9 14

TABLE 34 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 862 Dy Li 0.2:0.8:1:3.6 −12 40 863 Dy Zn 0.99:0.01:1:4.0 −5 30 864 Dy Zn 0.2:0.8:1:3.8 −21 45 865 Dy Pb 0.99:0.01:1:3.6 −15 27 866 Dy Pb 0.2:0.8:1:3.6 −18 24 867 Dy Ba 0.99:0.01:1:3.9 −12 14 868 Dy Ba 0.2:0.8:1:4.0 −5 20 869 Dy Ca 0.99:0.01:1:3.8 −8 19 870 Dy Ca 0.2:0.8:1:4.0 −6 30 871 Dy Al 0.99:0.01:1:4.0 −9 24 872 Dy Al 0.2:0.8:1:4.1 −12 22 873 Dy Bi 0.99:0.01:1:4.2 −5 30 874 Dy Bi 0.2:0.8:1:4.4 −21 41 875 Dy Y 0.99:0.01:1:4.2 −20 29 876 Dy Y 0.2:0.8:1:4.3 −5 34 877 Dy La 0.99:0.01:1:4.0 −8 27 878 Dy La 0.2:0.8:1:4.1 −12 32 879 Dy Ce 0.99:0.01:1:4.2 −20 19 880 Dy Ce 0.2:0.8:1:4.4 −8 15 881 Dy Pr 0.99:0.01:1:4.1 −5 25 882 Dy Pr 0.2:0.8:1:4.2 −8 33 883 Dy Nd 0.99:0.01:1:4.3 −10 34 884 Dy Nd 0.2:0.8:1:4.2 −6 30 885 Dy Sm 0.99:0.01:1:4.1 −18 22 886 Dy Sm 0.2:0.8:1:4.0 −5 19 887 Dy Eu 0.99:0.01:1:3.9 −8 24

TABLE 35 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 888 Dy Eu 0.2:0.8:1:4.1 −6 35 889 Dy Gd 0.99:0.01:1:4.0 −9 30 890 Dy Gd 0.2:0.8:1:3.9 −12 43 891 Dy Tb 0.99:0.01:1:4.2 −5 14 892 Dy Tb 0.2:0.8:1:4.1 −21 40 893 Dy Ho 0.99:0.01:1:4.2 −18 30 894 Dy Ho 0.2:0.8:1:4.3 −20 45 895 Dy Er 0.99:0.01:1:4.1 −18 27 896 Dy Er 0.2:0.8:1:4.2 −5 24 897 Dy Tm 0.99:0.01:1:4.0 −8 14 898 Dy Tm 0.2:0.8:1:4.1 −6 20 899 Dy Lu 0.99:0.01:1:4.2 −9 19 900 Dy Lu 0.2:0.8:1:4.3 −12 30 901 Ho — 1:0:1:4.1 −5 24 902 Ho Na 0.99:0.01:1:3.8 −21 22 903 Ho Na 0.2:0.8:1:3.9 −15 30 904 Ho K 0.99:0.01:1:3.6 −18 41 905 Ho K 0.2:0.8:1:3.9 −12 29 906 Ho Li 0.99:0.01:1:3.9 −5 34 907 Ho Li 0.2:0.8:1:3.8 −18 27 908 Ho Zn 0.99:0.01:1:4.1 −20 32 909 Ho Zn 0.2:0.8:1:4.0 −12 19 910 Ho Pb 0.99:0.01:1:3.8 −5 15 911 Ho Pb 0.2:0.8:1:4.0 −8 25 912 Ho Ba 0.99:0.01:1:4.0 −6 30 913 Ho Ba 0.2:0.8:1:4.0 −9 43

TABLE 36 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 914 Ho Ca 0.99:0.01:1:3.9 −12 14 915 Ho Ca 0.2:0.8:1:3.9 −5 40 916 Ho Al 0.99:0.01:1:4.2 −9 30 917 Ho Al 0.2:0.8:1:4.1 −12 45 918 Ho Bi 0.99:0.01:1:4.3 −5 27 919 Ho Bi 0.2:0.8:1:4.4 −5 24 920 Ho Y 0.99:0.01:1:4.2 −8 14 921 Ho Y 0.2:0.8:1:4.0 −12 20 922 Ho La 0.99:0.01:1:42 −20 19 923 Ho La 0.2:0.8:1:4.1 −8 30 924 Ho Ce 0.99:0.01:1:4.2 −5 22 925 Ho Ce 0.2:0.8:1:4.2 −8 19 926 Ho Pr 0.99:0.01:1:4.0 −10 24 927 Ho Pr 0.2:0.8:1:4.1 −6 35 928 Ho Nd 0.99:0.01:1:3.9 −18 30 929 Ho Nd 0.2:0.8:1:4.1 −5 43 930 Ho Sm 0.99:0.01:1:4.2 −8 14 931 Ho Sm 0.2:0.8:1:4.1 −6 40 932 Ho Eu 0.99:0.01:1:4.0 −9 30 933 Ho Eu 0.2:0.8:1:4.1 −12 45 934 Ho Gd 0.99:0.01:1:4.0 −5 27 935 Ho Gd 0.2:0.8:1:4.0 −21 24 936 Ho Tb 0.99:0.01:1:3.9 −18 14 937 Ho Tb 0.2:0.8:1:4.1 −20 20 938 Ho Dy 0.99:0.01:1:4.2 −18 19 939 Ho Dy 0.2:0.8:1:4.0 −5 30

TABLE 37 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 940 Ho Er 0.99:0.01:1:4.2 −8 24 941 Ho Er 0.2:0.8:1:4.1 −6 22 942 Ho Tm 0.99:0.01:1:3.9 −9 30 943 Ho Tm 0.2:0.8:1:4.2 −12 41 944 Ho Lu 0.99:0.01:1:4.2 −5 29 945 Ho Lu 0.2:0.8:1:4.3 −8 34 946 Er — 1:0:1:4.0 −12 27 947 Er Na 0.99:0.01:1:3.6 −8 32 948 Er Na 0.2:0.8:1:3.9 −5 19 949 Er K 0.99:0.01:1:3.7 −8 15 950 Er K 0.2:0.8:1:3.8 −10 25 951 Er Li 0.99:0.01:1:3.8 −6 30 952 Er Li 0.2:0.8:1:3.6 −6 43 953 Er Zn 0.99:0.01:1:4.0 −8 14 954 Er Zn 0.2:0.8:1:3.8 −12 40 955 Er Pb 0.99:0.01:1:3.6 −10 30 956 Er Pb 0.2:0.8:1:3.6 −8 45 957 Er Ba 0.99:0.01:1:3.9 −8 27 958 Er Ba 0.2:0.8:1:4.0 −23 24 959 Er Ca 0.99:0.01:1:3.8 −27 14 960 Er Ca 0.2:0.8:1:4.0 −18 20 961 Er Al 0.99:0.01:1:4.0 −15 32 962 Er Al 0.2:0.8:1:4.1 −8 19 963 Er Bi 0.99:0.01:1:4.2 −12 15 964 Er Bi 0.2:0.8:1:4.4 −10 25 965 Er Y 0.99:0.01:1:4.2 −19 30

TABLE 38 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 966 Er Y 0.2:0.8:1:4.3 −25 43 967 Er La 0.99:0.01:1:4.0 −14 14 968 Er La 0.2:0.8:1:4.1 −12 40 969 Er Ce 0.99:0.01:1:4.2 −5 30 970 Er Ce 0.2:0.8:1:4.4 −8 45 971 Er Pr 0.99:0.01:1:4.1 −6 27 972 Er Pr 0.2:0.8:1:4.2 −9 24 973 Er Nd 0.99:0.01:1:4.3 −8 14 974 Er Nd 0.2:0.8:1:4.2 −5 20 975 Er Sm 0.99:0.01:1:4.1 −8 32 976 Er Sm 0.2:0.8:1:4.0 −10 19 977 Er Eu 0.99:0.01:1:3.9 −12 15 978 Er Eu 0.2:0.8:1:4.1 −5 25 979 Er Gd 0.99:0.01:1:4.0 −18 30 980 Er Gd 0.2:0.8:1:3.9 −20 43 981 Er Tb 0.99:0.01:1:4.2 −12 14 982 Er Tb 0.2:0.8:1:4.1 −5 40 983 Er Dy 0.99:0.01:1:4.2 −8 30 984 Er Dy 0.2:0.8:1:4.3 −6 45 985 Er Ho 0.99:0.01:1:4.1 −9 27 986 Er Ho 0.2:0.8:1:4.2 −12 24 987 Er Tm 0.99:0.01:1:4.0 −5 14 988 Er Tm 0.2:0.8:1:4.1 −9 20 989 Er Lu 0.99:0.01:1:4.2 −12 32 990 Er Lu 0.2:0.8:1:4.3 −5 19 991 Tm — 1:0:1:4.1 −5 15

TABLE 39 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 992 Tm Na 0.99:0.01:1:3.9 −8 25 993 Tm Na 0.2:0.8:1:3.8 −12 30 994 Tm K 0.99:0.01:1:3.8 −20 43 995 Tm K 0.2:0.8:1:4.0 −8 14 996 Tm Li 0.99:0.01:1:4.1 −5 24 997 Tm Li 0.2:0.8:1:3.9 −8 35 998 Tm Zn 0.99:0.01:1:4.2 −10 30 999 Tm Zn 0.2:0.8:1:4.0 −9 43 1000 Tm Pb 0.99:0.01:1:4.0 −12 14 1001 Tm Pb 0.2:0.8:1:3.9 −5 40 1002 Tm Ba 0.99:0.01:1:3.9 −21 30 1003 Tm Ba 0.2:0.8:1:4.0 −18 45 1004 Tm Ca 0.99:0.01:1:4.0 −20 27 1005 Tm Ca 0.2:0.8:1:4.0 −18 24 1006 Tm Al 0.99:0.01:1:3.9 −5 14 1007 Tm Al 0.2:0.8:1:4.2 −8 20 1008 Tm Bi 0.99:0.01:1:4.4 −6 19 1009 Tm Bi 0.2:0.8:1:4.3 −9 30 1010 Tm Y 0.99:0.01:1:4.0 −12 24 1011 Tm Y 0.2:0.8:1:4.2 −5 22 1012 Tm La 0.99:0.01:1:4.1 −21 30 1013 Tm La 0.2:0.8:1:3.9 −15 41 1014 Tm Ce 0.99:0.01:1:3.9 −18 29 1015 Tm Ce 0.2:0.8:1:4.2 −12 34 1016 Tm Pr 0.99:0.01:1:4.1 −5 27 1017 Tm Pr 0.2:0.8:1:4.0 −18 32

TABLE 40 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 1018 Tm Nd 0.99:0.01:1:4.3 −20 19 1019 Tm Nd 0.2:0.8:1:4.2 −12 15 1020 Tm Sm 0.99:0.01:1:4.0 −5 25 1021 Tm Sm 0.2:0.8:1:4.1 −8 30 1022 Tm Eu 0.99:0.01:1:4.0 −6 43 1023 Tm Eu 0.2:0.8:1:4.0 −9 14 1024 Tm Gd 0.99:0.01:1:3.9 −12 40 1025 Tm Gd 0.2:0.8:1:4.2 −9 30 1026 Tm Tb 0.99:0.01:1:4.1 −12 45 1027 Tm Tb 0.2:0.8:1:4.0 −5 27 1028 Tm Dy 0.99:0.01:1:4.2 −21 24 1029 Tm Dy 0.2:0.8:1:4.1 −18 14 1033 Tm Ho 0.99:0.01:1:4.3 −10 20 1031 Tm Ho 0.2:0.8:1:3.9 −12 19 1032 Tm Er 0.99:0.01:1:4.0 −5 19 1033 Tm Er 0.2:0.8:1:4.2 −18 30 1034 Tm Lu 0.99:0.01:1:4.1 −20 24 1035 Tm Lu 0.2:0.8:1:4.2 −12 22 1036 Lu — 1:0:1:4.0 −5 30 1037 Lu Na 0.99:0.01:1:3.6 −8 41 1038 Lu Na 0.2:0.8:1:3.9 −6 29 1039 Lu K 0.99:0.01:1:3.7 −9 34 1040 Lu K 0.2:0.8:1:3.8 −12 27 1041 Lu Li 0.99:0.01:1:3.8 −5 32 1042 Lu Li 0.2:0.8:1:3.6 −9 19 1043 Lu Zn 0.99:0.01:1:4.0 −12 15

TABLE 41 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 1044 Lu Zn 0.2:0.8:1:3.8 −5 25 1045 Lu Pb 0.99:0.01:1:3.6 −5 30 1046 Lu Pb 0.2:0.8:1:3.6 −8 43 1047 Lu Ba 0.99:0.01:1:3.9 −12 14 1048 Lu Ba 0.2:0.8:1:4.0 −20 40 1049 Lu Ca 0.99:0.01:1:3.8 −8 30 1050 Lu Ca 0.2:0.8:1:4.0 −23 45 1051 Lu Al 0.99:0.01:1:4.0 −27 27 1052 Lu Al 0.2:0.8:1:4.1 −18 24 1053 Lu Bi 0.99:0.01:1:4.2 −15 14 1054 Lu Bi 0.2:0.8:1:4.4 −8 20 1055 Lu Y 0.99:0.01:1:4.2 −12 32 1056 Lu Y 0.2:0.8:1:4.3 −10 19 1057 Lu La 0.99:0.01:1:4.0 −19 15 1058 Lu La 0.2:0.8:1:4.1 −5 25 1059 Lu Ce 0.99:0.01:1:4.2 −8 30 1060 Lu Ce 0.2:0.8:1:4.4 −6 43 1061 Lu Pr 0.99:0.01:1:4.1 −9 14 1062 Lu Pr 0.2:0.8:1:4.2 −12 30 1063 Lu Nd 0.99:0.01:1:4.3 −9 43 1064 Lu Nd 0.2:0.8:1:4.2 −12 14 1065 Lu Sm 0.99:0.01:1:4.1 −5 40 1066 Lu Sm 0.2:0.8:1:4.0 −21 30 1067 Lu Eu 0.99:0.01:1:3.9 −18 45 1068 Lu Eu 0.2:0.8:1:4.1 −10 27 1069 Lu Gd 0.99:0.01:1:4.0 −12 24

TABLE 42 (Ln_(1−x)M_(x))₂NiO_(y) Electrical Seebeck coefficient resistivity at 700° C. at 700° C. No. Ln M 0.5Ln:0.5M:Ni:O (μVK⁻¹) (mΩcm) 1070 Lu Gd 0.2:0.8:1:3.9 −5 14 1071 Lu Tb 0.99:0.01:1:4.2 −18 20 1072 Lu Tb 0.2:0.8:1:4.1 −20 19 1073 Lu Dy 0.99:0.01:1:4.2 −12 19 1074 Lu Dy 0.2:0.8:1:4.3 −5 30 1075 Lu Ho 0.99:0.01:1:4.1 −8 24 1076 Lu Ho 0.2:0.8:1:4.2 −6 22 1077 Lu Er 0.99:0.01:1:4.0 −9 30 1078 Lu Er 0.2:0.8:1:4.1 −5 41 1079 Lu Tm 0.99:0.01:1:4.2 −8 29 1080 Lu Tm 0.2:0.8:1:4.3 −12 34 

1. A complex oxide having a composition represented by the formula Ln1-xMxNiOy; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; and 0≦x≦0.8; and 2.7≦y≦3.3, the complex oxide having a negative Seebeck coefficient at 100° C. or higher.
 2. A complex oxide having a composition represented by the formula Ln1-xMxNiOy; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8; and 2.7≦y≦3.3, the complex oxide having an electrical resistivity of 1 Ωcm or less at 100° C. or higher.
 3. A complex oxide having a composition represented by the formula (Ln1-xMx)2NiOy; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8; and 3.6≦y≦4.4, the complex oxide having a negative Seebeck coefficient at 100° C. or higher.
 4. A complex oxide having a composition represented by the formula (Ln1-xMx)2NiOy; wherein Ln is a lanthanide, M is at least one element selected from the group consisting of Na, K, Li, Zn, Pb, Ba, Ca, Al, Bi, and rare earth elements being not the same as Ln; 0≦x≦0.8, and 3.6≦y≦4.4, the complex oxide having an electrical resistivity of 1 Ωcm or less at 100° C. or higher.
 5. An n-type thermoelectric material comprising the complex oxide of claim
 1. 6. A thermoelectric module comprising the n-type thermoelectric material of claim
 5. 